If anyone finds an $80M F-35 stealth fighter, please call the Pentagon

Updated Anyone who has ever misplaced their car keys can sympathize with the US military, which has reportedly lost one of its F-35 stealth fighters after the pilot ejected but the aircraft continued flying, and is now seeking public help to find it.

The plane in question, a US Marine Corps F-35B said to belong to one of the Marine Fighter Attack Training Squadrons, went missing after a "mishap" on Sunday afternoon, September 17, led to the pilot ejecting, but not before he put the aircraft on autopilot.

The stealth fighter took off from Marine Corps Air Station Beaufort in South Carolina accompanied by another, which returned safely to the airfield. The pilot ejected for reasons that have yet to be explained.

According to ABC News, the pilot parachuted safely into a North Charleston neighborhood at about 2pm local time and was then taken to hospital, but he is said to be in a stable condition.

Searches are focusing on the area surrounding two large bodies of water, Lake Moultrie and Lake Marion, based on the plane's last known position and direction of travel.

This area is to the north of another military base, Joint Base Charleston under the jurisdiction of the US Air Force, which is working with Air Station Beaufort to locate the missing plane.

In fact, the base posted the incident on social media, requesting the public's assistance in locating the $80 million aircraft.

"We're working with @MCASBeaufortSC to locate an F-35 that was involved in a mishap this afternoon. The pilot ejected safely. If you have any information that may help our recovery teams locate the F-35, please call the Base Defense Operations Center at 843-963-3600," it tweeted.

The problem, according to The Washington Post, is that the F-35's transponder, which would otherwise help to locate the aircraft, was not working for reasons that are also not clear.

Another issue is that the F-35 was famously designed to be stealthy, making it difficult to detect by radar. The aircraft has special coatings to absorb radar energy, and its faceted design is intended to direct any radar energy that does get reflected away from the source that emitted it.

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For this reason, F-35 aircraft can be fitted with radar reflectors when not on operational sorties, which includes transit flights and many training missions, so that they are visible to military radar and air traffic control. However, it is not clear what the nature of the mission was in this case, so reflectors may not have been present.

According to The War Zone, if the aircraft was in its full stealth configuration and the problems that led the pilot to eject were caused by onboard avionics systems failures, tracking it may have been very difficult.

We contacted the Pentagon press office to ask for further details, which directed us to contact the US Marine Corps directly, and we are awaiting a response.

This is not the first "mishap" involving the F-35. Last year, an F-35C ended up in the sea after an underpowered approach to the aircraft carrier USS Carl Vinson. Pilot error was blamed.

The F-35B involved in the latest incident is the short take-off and vertical landing (STOVL) version of the plane, which is also operated by the UK's Royal Navy. One of these suffered an accident aboard the aircraft carrier HMS Queen Elizabeth in 2021, ending up in the ocean.

In that case, an investigation found that the cause was an intake blank, designed to plug the air inlet to the aircraft's jet engine when it is not in flight, which had mistakenly been left in place when it was prepared to go on a training mission. ®

Updated to add

A US Marine Corps spokesperson issued the following statement, indicating that the aircraft has still not been found and using the word "mishap" three times.

"We can confirm a mishap involving an F-35B Lightning II jet from Marine Fighter Attack Training Squadron (VMFAT) 501 with the 2nd Marine Aircraft Wing, Sept. 17. The pilot safely ejected from the aircraft," the organization said.

"The search-and-recovery efforts for the aircraft are ongoing, and we are thankful to the agencies assisting in this effort. The mishap is currently under investigation. The Department of the Navy has a well-defined process for investigating aircraft mishaps. We are unable to provide additional details to preserve the integrity of the investigatory process."